JPH04338670A - Heat sink mounting mechanism - Google Patents

Abstract

PURPOSE:To easily modify a component mounting, soldering and wiring patterns by detachably mounting a heat sink on an LSI case. CONSTITUTION:A U-shaped clip 2 is secured to a heat radiating surface 1a of an LSI case 1. A flat part 3a held by the clip 2 is provide at a center of a heat sink 3. When the sink 3 is mounted on the case 1, the part 3a is inserted into the clip 2 on the surface 1a of the case 1. The clip 2 holds the part 3a of the sink 2 by a retaining part 2a by its elastic force, and secures the sink 3 on the surface 1a of the case 1.

Description

[Detailed description of the invention]

0001

[Technical Field] The present invention relates to a heat sink mounting mechanism.
In particular, the present invention relates to a mounting mechanism for a heat sink for cooling semiconductor devices and the like.

0002

2. Description of the Related Art Conventionally, as shown in FIG. 4, this type of heat sink mounting mechanism has been constructed by attaching a good material such as silver particles to an LSI case 10 that houses a semiconductor element 6 and is mounted on a printed circuit board 5 by leads 4. There is a structure in which the heat sink 11 is bonded with an adhesive 12 containing a thermally conductive filler.

Further, as shown in FIG. 5, a stud 21 is provided as a heat transfer plate for an LSI case 20 that houses a semiconductor element 6 and is mounted on a printed circuit board 5 via leads 4.
There is also a structure in which a stud 21 is fitted into a slit 22a of a heat sink 22 as shown in FIG. 6, and the heat sink 22 is pressed against the side surface of the stud 21. The above structure is detailed in Japanese Patent Application Laid-Open No. 58-25249.

Furthermore, in recent years, as semiconductor elements 6 have become more highly integrated and faster, the amount of heat generated by semiconductor elements 6 has increased, and there is a tendency for heat sinks 11 and 22 to become larger.

In such a conventional heat sink mounting mechanism, the heat sink 11 is attached to the LSI case 1 using adhesive 12.
If the structure is to be bonded to 0, once bonded, the LSI
Since the heat sink 11 cannot be removed from the case 10, when mounting surface-mounted components such as flat packs on both sides of the printed board 5, the components are mounted on one side of the printed board 5, and then the components are mounted on the other side. When mounting the printed circuit board 5, it is difficult to hold the printed board 5 due to the unevenness of the heat sink 11, which poses a problem when mounting components or soldering.

[0006] Furthermore, as the heat sinks 11 and 22 become larger and their heat capacity increases due to the increase in the amount of heat generated by the semiconductor elements 6 due to higher integration and higher speeds, uneven heating occurs during the soldering process. The problem was that it became a hindrance.

Furthermore, when modifying the wiring pattern of the printed circuit board 5 after assembly, there is a problem in that the presence of the heat sinks 11 and 22 makes it difficult to cut the pattern or add wiring.

In the case of a flat pack type LSI case, it is necessary to make the leads visible for soldering and inspection, and when the heat sink is larger than the LSI case and hides the leads, the heat sink There was a problem in that it could not be attached to an LSI case.

[0009]

OBJECTS OF THE INVENTION The present invention has been made in order to eliminate the problems of the conventional ones as described above, and it is possible to freely attach and detach a heat sink to an LSI case, and to perform component mounting, soldering, and wiring patterns. The purpose of the present invention is to provide a heat sink mounting mechanism that can be easily modified.

0010

[Structure of the Invention] A heat sink mounting mechanism according to the present invention includes a storage case that stores a semiconductor element inside, a heat sink that radiates heat transferred from a heat radiation surface of the storage case, and a heat sink that is fixed on the heat radiation surface of the storage case. and a clip that holds the bottom surface of the heat sink.

[0011]

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view of an embodiment of the present invention.
FIG. 2 is a front view of one embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2 in the direction of arrows. In these figures, a semiconductor element 6 is housed inside an LSI case 1 mounted on a printed circuit board 5 by leads 4, and the surface opposite to the housing surface of this semiconductor element 6 is a heat dissipation surface 1.
It has become a. A U-shaped clip 2 is fixed onto the heat radiation surface 1a by brazing, gluing, or the like.

A flat portion 3a is provided at the center of the heat sink 3 and is held between the clips 2. LSI
When attaching the heat sink 3 to the case 1, its flat portion 3a is inserted into the clip 2 on the heat radiation surface 1a of the LSI case 1. As a result, the holding portion 2a pinches the flat portion 3a of the heat sink 3 due to the elastic force of the clip 2, so that the heat sink 3 is fixed on the heat radiation surface 1a of the LSI case 1.

Since the clip 2 is made of a material with good thermal conductivity, the heat generated by the semiconductor element 6 is transferred to the LSI.
Heat is transmitted from the heat radiation surface 1a of the case 1 to the heat sink 3 via the clip 2, and is radiated from the heat sink 3 into the air. In this case, the heat sink 3 is connected to the L through the clip 2.
This means that it is in contact with the heat radiation surface 1a of the SI case 1. Further, since the heat sink 3 is only fixed by the elastic force of the clip 2, the heat sink 3 can be freely attached to and detached from the LSI case 1.

In this manner, by holding the flat portion 3a of the heat sink 3 between the clips 2 fixed to the heat dissipation surface 1a of the LSI case 1 that houses the semiconductor element 6 therein, the heat sink 3 is held against the LSI case 1. Can be installed and removed freely.

Since the heat sink 3 can be freely removed from the LSI case 1, the LSI case 1 can be removed from the printed board 5.
The heat sink 3 does not become an obstacle when soldering to or inspecting, or when modifying the wiring pattern of the printed board 5.

Furthermore, even if the heat sink 3 becomes larger and has a larger heat capacity, the heat sink 3 can be removed from the LSI case 1, so that uneven heating does not occur during the soldering process, making the soldering process easier.

Furthermore, even in the case of a surface-mounted LSI case such as a flat pack, the heat sink can be removed, so even a large heat sink that hides the leads can be used.

In one embodiment of the present invention, the heat sink 3
Although the center portion of the heat sink 3 is held between the clips 2, the vicinity of both ends of the heat sink 3 may be held between a plurality of clips 2. Further, the shape of the heat dissipation surface 1a of the LSI case 1 may be such that it directly contacts the heat sink 3 when the heat sink 3 is held between the clips 2, but is not limited thereto.

[0020]

[Effects of the Invention] As explained above, according to the present invention, the bottom surface of the heat sink is held between the clips fixed on the heat dissipation surface of the storage case in which the semiconductor elements are stored, so that the LSI case can be This has the effect that the heat sink can be freely attached and detached, and parts mounting, soldering, and wiring patterns can be easily modified.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is a front view of one embodiment of the present invention.

FIG. 3 is a cross-sectional view taken along line AA in FIG. 2 in the direction of arrows.

FIG. 4 is a vertical cross-sectional view of a conventional example.

FIG. 5 is a vertical cross-sectional view of a conventional example.

FIG. 6 is a plan view of the heat sink of FIG. 5;

[Explanation of symbols]

1 LSI case 2 Clip 2a Presser part 3 Heat sink 3a Flat part

Claims (1)

[Claims] 1. A storage case that stores a semiconductor element inside, a heat sink that dissipates heat transferred from a heat radiation surface of the storage case, and a heat sink that is fixed to the heat radiation surface of the storage case and holds the bottom surface of the heat sink. A heat sink mounting mechanism characterized by comprising a clip for attaching the heat sink.